U.S. EPA Region 9, Memorandum to File, April 26, 2016 

Sample emission reduction calculations for selected Carl Moyer and Prop 1B projects 

Docket No. EPA-R09-OAR-2015-0489 

1 

Sample Carl Moyer Project Calculations 

From Appendix H.1, which lists the Moyer projects included in the Emission Reduction 

Report, we randomly selected the following projects: 

Project Number 

G-0014-A 

S-1301 

C-2570 

C-14205 

Of these projects, ARB provided information regarding G-0014-A, stating: 

“We have included data for this item as requested. However, this project should not be 

included in the San Joaquin Valley Incentive-Based Emission Reduction Measures List. 

It is not a San Joaquin Valley project and San Joaquin Valley staff plan to fix the error. 

All San Joaquin Valley Carl Moyer Program Projects are denoted with a "C", "S", or "N" 

in the Project Number. San Joaquin Valley staff administer the Carl Moyer Program on 

behalf of Great Basin Unified Air Pollution Control District and identify these projects 

with a "G." This error was an isolated issue and no other projects requesting credit under 

the Carl Moyer Program begin with a "G." 1

We present below a sample calculation for the next project on the list: “S-1301.” From 

page 5 of Appendix H.1, we obtained the following project information: 

Project

Number

Carl 

Moyer 

Guideline

Equipment

Identifier 

Source 

Category 

Technology

Post

Inspection 

Date 

Project

Life 

2014 

NOx 

(tpy) 

2014 

PM2.5 

(tpy) 

S-1301 2005 1 Off-Road 

Equipment -

Mobile 

Agricultural

Repower 10/16/2009 7 2.610 0.092 

Appendix C of the 2005 Carl Moyer Guidelines contains the formulas used to determine 

annual emissions and annual emission reductions based on usage information, including options 

for using hours of operation, fuel consumption and miles traveled to determine annual usage. 

Formula C-4 in Appendix C (see 2005 Carl Moyer Guidelines, Appendix C at p. C-3) is used to 

calculate annual emissions within the San Joaquin Valley based on hours of operation. Appendix 

B, Tables for Emission Reduction and Cost-Effectiveness Calculations, of the 2005 Carl Moyer 

Guidelines has tables containing the data needed to calculate the emission reductions of projects 

using formulas in Appendix C. 

Emissions = EF * hp * LF* Activity * Fraction Operation in the SJV * (1 ton /907,200 g) 

Where: 

 

1 See file “Attachement.xlsx” included in email from Austin Hicks (ARB) to Andrew Steckel (EPA R9), dated 

12/3/2015. 
U.S. EPA Region 9, Memorandum to File, April 26, 2016 

Sample emission reduction calculations for selected Carl Moyer and Prop 1B projects 

Docket No. EPA-R09-OAR-2015-0489 

2 

Emissions = tons per year calculated independently for both the existing and replacement 

engines 

EF = Emission Factor in grams per brake horsepower-hour, obtained from Table B-12 

(see 2005 Car Moyer Appendix B at pp. B-11) 

hp = horsepower of the engine 

LF = Load Factor, obtained from Table B-13 (Appendix B at p. B-12) 

Activity = hours per year 

Formula C-10 in Appendix C is used to calculate the emission reductions by pollutant: 

Emission Reductions = Emissions baseline – Emissionsreduced 

Where: Emissions baseline is the Annual Emissions for the Baseline Technology 

 Emissionsreduced is the Annual Emissions for the Reduced Technology 

We use the following project-specific information obtained from the ARB upon request2, both as 

inputs in the above equation and to look up the EFs and LFs in Appendix B. 

Engine Project Number S-1301

Equipment Identifier 1 

Equipment Category Off-Road Ag. Repower 

Equipment Type Other 

Annual Hours of Operation 1800 

Percent Operated in SJV District 100% 

Baseline Fuel Type Diesel 

Engine Year 1981 

Horsepower 320 

Engine Certification Uncontrolled 

Reduced Fuel Type Diesel 

Engine Year 2009 

Horsepower 300 

Engine Certification Tier 3 Standard 

We use the equipment category, engine year, horsepower and engine certification shown above 

to obtain the following EFs and LFs, from Tables B-12 and B-13 respectively: 

LF 0.51 

Baseline NOx EF 10.23 

PM EF 0.382 

Reduced NOx EF 2.32 

PM EF 0.088 

NOx Emissions baseline = 10.23 * 320 *0.51* 1800 * 1 * (1 ton /907,200 g) 

 = 3.31 tpy 

NOx Emissionsreduced = 0.704 tpy 

NOx Emission Reductions = 2.61 

 

2 See file “Attachement.xlsx” included in email from Austin Hicks (ARB) to Andrew Steckel (EPA R9), dated 

12/3/2015. 
U.S. EPA Region 9, Memorandum to File, April 26, 2016 

Sample emission reduction calculations for selected Carl Moyer and Prop 1B projects 

Docket No. EPA-R09-OAR-2015-0489 

3 

This is consistent with the data in Appendix H.1 for Carl Moyer project S-1301. 

PM Emissions baseline = 0.382 * 320 *0.51* 1800 * 1 * (1 ton /907,200 g) 

 = 0.124 tpy 

PM Emissionsreduced = 0.027 tpy 

PM Emission Reductions = 0.97 tpy 

ARB clarified that there is a conversion ratio for Moyer calculations of 0.92 PM2.5 to the PM10

totals of exhaust. 3 Using this conversion factor, 

PM2.5 Emission Reductions = 0.92 * PM Emission Reductions 

 = 0.92 * 0.097 tpy 

 = 0.089 tpy. 

This is consistent with the data in Appendix H.1 for Carl Moyer project S-1301 (0.092), taking 

rounding errors at the third decimal point into account. 

The Table below shows the emission reduction values (in tpy) reported in Appendix H.1 of the 

Emission Reduction Report and calculated by EPA for the projects randomly chosen.4

Project Number Equipment 

Identifier 

Reported 

NOx

Reported 

PM2.5

NOx Calculated 

by EPA 

PM2.5 Calculated 

by EPA

S-1301 1 2.61 0.092 2.61 0.089

3 4.04 0.120 4.04 0.124

C-2570 1 7.07 0.129 7.07 0.132

2 9.88 0.331 9.88 0.328

C-14205 1 1.57 0.055 1.57 0.055

As shown in the table, we have verified that the calculated emission reductions for all example 

projects were consistent to the second decimal. 

 

 

3 See email from Austin Hicks (ARB) to Idalia Pérez (EPA R9), dated 12/10/2015 regarding “Responses to Followup Questions.” 

4 Not including the Great Basin project per ARB’s explanation above. 
U.S. EPA Region 9, Memorandum to File, April 26, 2016 

Sample emission reduction calculations for selected Carl Moyer and Prop 1B projects 

Docket No. EPA-R09-OAR-2015-0489 

4 

Sample Prop 1B Project Calculations 

From Appendix H.2, which lists the Prop 1B projects included in the Emission Reduction 

Report, we selected the following projects: 

Equipment Project ID 

G08GMCT1_03079 

G08GMCT1_00642 

G08GMCT1_02930 

G07GMCT3_01246 

G07GMCT3_00301 

G07GMCT3_00437 

G07GMCT3_00377 

We used the publicly available Project Benefits Calculator 5and information provided by 

ARB6to verify the emission reductions. Specifically, we obtained information about each project 

from ARB,7 such as the VMT, model year and fuel type of the old engine and the gross vehicle 

weight rating (GVWR) for the old and new engines, and entered those data into the “data input” 

tab in the corresponding Project Benefits Calculator. Based on these inputs, we divided the 

“lifetime” emission reductions calculated by the Project Benefits Calculator by the total lifetime 

of the projects to obtain the reductions for 2014.8 

The table below shows some discrepancies between our calculations of the emission reductions 

(in lbs/year) and those provided in Appendix H.2 of the Emission Reduction Report. 

Equipment Project 

ID9

Reported 

NOx

Reported 

PM 

NOx calculated 

by EPA 

PM calculated 

by EPA 

G08GMCT1_03079 10281.32 229.63 10076.13 241.45

G08GMCT1_00642 1725.00 164.04 1680.75 176.64

G08GMCT1_02930 0.00 0.00 3374.45 1.47

G07GMCT3_01246 8012.63 235.70 8012.63 256.20

G07GMCT3_00301 394.22 22.10 2699.61 161.15

G07GMCT3_00437 3756.23 110.50 3938.27 127.78

G07GMCT3_00377 2909.29 92.69 3873.68 136.50

 

5 See email from Sylvia Vanderspek (ARB) to Andrew Steckel (EPA R9), dated 11/12/2015 regarding “Information 

request to support final action on ARB Incentive Report.” Note that ARB’s email refers to “online truck calculators” 

in reference to what the Prop 1B Guidelines call “Project Benefits Calculator.” 

6 See file “Attachement.xlsx” included in email from Austin Hicks (ARB) to Andrew Steckel (EPA R9), dated 

12/3/2015. 

7 See file “Attachement.xlsx” included in email from Austin Hicks (ARB) to Andrew Steckel (EPA R9), dated 

12/3/2015. 

8 The Project Benefits Calculator calculates the “lifetime” emission reduction in pounds, which we then multiplied 

by 0.0005 (1 ton per 2000 pounds) to obtain the equivalent tonnage. 

9

 Equipment Project IDs starting with “G08” are subject to the 2010 Prop 1B Guidelines. Equipment Project IDs 

starting with “G07” are subject to the 2008 Prop 1B Guidelines. 
U.S. EPA Region 9, Memorandum to File, April 26, 2016 

Sample emission reduction calculations for selected Carl Moyer and Prop 1B projects 

Docket No. EPA-R09-OAR-2015-0489 

5 

Information provided by ARB10 indicates that the differences are due to ARB using a 

different methodology (GMOD) to calculate the emission reductions, instead of using the Project 

Benefits Calculators available on the ARB website. Broadly, the differences are due to the 

inability of the Project Benefits Calculators to account for compliance deadlines in ARB’s Truck 

and Bus Regulation and the emissions that occur specifically within the SJV trade corridor, and 

its use of emission factors different than those used by GMOD. 

Additional information that ARB provided clarified the calculation methodology11 for 

both 2008 and 2010 Prop 1B projects, included additional inputs12 needed for the calculation and 

corrected inputs for the calculations which were incorrectly reported.13 The table below shows 

the corrected data from ARB used to verify the Prop 1B calculations. 

Equipment Project ID Input variable Incorrect Value14 Correct value15

G08GMCT1_03079 New Engine Model Year 2010 2011 

G08GMCT1_00642 Old Engine Model Year 1977 1973 

G08GMCT1_00642 New Engine Model Year 2010 2012 

G07GMCT3_00301 New VMT (if different) n/a 70,000 

For Prop 1B projects subject to the 2008 Guidelines, the methodology for determining 

emission reductions is as described above using the Project Benefits Calculator, but the values 

obtained are corrected for the percentage of vehicle miles travelled in San Joaquin Valley, and 

the PM values are additionally corrected to account for the percentage of total PM that is PM2.5

(92%), as in the Carl Moyer example above. 

NOx Emissions Reductions = Total NOx Benefits (lbs) * %SJV Op 

Where: 

Total NOx Benefits (lbs) is obtained from the Project Benefits Calculator 

%SJV Op = Percent operation of the vehicle in San Joaquin Valley 

The Table below shows the emission reduction values (in lbs/year) reported in Appendix 

H.2 of the Emission Reduction Report and the emission reductions calculated by EPA for the 

four randomly chosen projects subject to the 2008 Prop 1B guidelines. 

 

10 See email from Sylvia Vanderspek (ARB) to Andrew Steckel (EPA R9), dated 3/9/2016 regarding “Prop 1 B 

Benefit calculator information.” 

11 See file “Prop 1B Emission Reduction Methodology to EPA v2.docx” included in email from Sylvia Vanderspek 

(ARB) to Jeanhee Hong (EPA R9), dated 4/19/2016. 

12 In addition to previously reported inputs, ARB included “Project Calendar Year” which had not been previously 

included. See file “Attachement Prop 1B Input Data.xlsx” included in email from Sylvia Vanderspek (ARB) to 

Jeanhee Hong (EPA R9), dated 4/19/2016. 

13 See file “Attachement.xlsx” included in email from Austin Hicks (ARB) to Andrew Steckel (EPA R9), dated 

12/3/2015. 

14 See file “Attachement.xlsx” included in email from Austin Hicks (ARB) to Andrew Steckel (EPA R9), dated 

12/3/2015. 

15 See file “Attachement Prop 1B Input Data.xlsx” included in email from Sylvia Vanderspek (ARB) to Jeanhee 

Hong (EPA R9), dated 4/19/2016. 
U.S. EPA Region 9, Memorandum to File, April 26, 2016 

Sample emission reduction calculations for selected Carl Moyer and Prop 1B projects 

Docket No. EPA-R09-OAR-2015-0489 

6 

Equipment Project 

ID16

Reported 

NOx

NOx calculated by 

EPA 

Reported 

PM 

PM calculated 

by EPA 

G07GMCT3_01246 8012.63 8012.63 235.70 235.70

G07GMCT3_00301 394.22 394.22 22.10 22.10

G07GMCT3_00437 3756.23 3756.23 110.50 110.50

G07GMCT3_00377 2909.29 2909.29 92.69 92.69

As shown in the table, we have verified that the calculated emission reductions for all example 

projects were consistent to the second decimal. 

For the three randomly chosen Prop 1B projects subject to the 2010 Prop 1B guidelines, 

the annual emissions are determined by the following equation17: 

Emissions = ER * VMT * %SJV Op * (1 lb. / 453.6 grams) 

Where: 

Emissions = pounds per year calculated independently for both the existing and 

replacement engines 

ER = Emission Rate (Emission Factor) in grams per mile 

VMT = Annual mileage accrual (miles/year) 

%SJV Op = Percent operation of the vehicle in San Joaquin Valley 

We use the following project-specific information obtained from the ARB upon request18, both 

as inputs in the above equation and to look up the appropriate ER in EMFAC19. 

Engine Project Number G08GMCT1_03079 

Project Calendar Year 2012 

Project Life (years) 5 

Percent VMT in San Joaquin Valley 99% 

Annual VMT 211,592 

Baseline Engine Year 2002 

GVWR 52,000 

Reduced Engine Year 2011 

GVWR 50,000 

NOx Certification Level 0.2 NOx

The emission rates for each engine used in the 2010 Prop 1B calculations take into account 

engine degradation, and hence vary by model year of the engine and by calendar year for which 

 

16 Equipment Project IDs starting with “G08” are subject to the 2010 Prop 1B Guidelines. Equipment Project IDs 

starting with “G07” are subject to the 2008 Prop 1B Guidelines. 

17 See the “Directions” tab in the “Project Benefits Calculator.” See also email from Sylvia Vanderspek (ARB) to 

Andrew Steckel (EPA R9), dated 11/12/2015 regarding “Information request to support final action on ARB 

Incentive Report.” Note that ARB’s email refers to “online truck calculators” in reference to what the Prop 1B 

Guidelines call “Project Benefits Calculator.” 

18 See file “Attachement Prop 1B Input Data.xlsx” included in email from Sylvia Vanderspek (ARB) to Jeanhee 

Hong (EPA R9), dated 4/19/2016. 

19 See file “Prop 1B G08 2010 Guideline Year Emission Factors (Year 2 EFs).xlsx” included in email from Austin 

Hicks (ARB) to Idalia Perez (EPA R9), dated 4/21/2016. 
U.S. EPA Region 9, Memorandum to File, April 26, 2016 

Sample emission reduction calculations for selected Carl Moyer and Prop 1B projects 

Docket No. EPA-R09-OAR-2015-0489 

7 

the emissions are calculated. EPA used the following emission rates to verify the calculation for 

project G08GMCT1_03079. 

Project 

year (i) 

Baseline20 Reduced21

CY_MY 

ER 

(NOx, g/mile) 

ER 

(PM, g/mile) Age

ER 

(NOx, g/mile) 

ER 

(PM, g/mile) 

1 2012_2002 23.70079375 0.594347923 0 1.139260843 0.049891932

2 2013_2002 23.89975617 0.610571162 1 1.393883507 0.059825792

3 2014_2002 23.90063252 0.61045971 2 1.581880106 0.066584192

4 2015_2002 23.90507227 0.611210898 3 1.821081778 0.075651562

5 2016_2002 23.91391461 0.6125756 4 2.068115279 0.084859811

Because the emission rates in the 2010 Prop 1B calculations take into account engine 

degradation, emission reduction are calculated for each year of the project life. 

Emission Reductions (i) = Emissions baseline, i – Emissionsreduced, i 

Where: 

Emissions baseline, i is the Annual Emissions in year “i” for the Baseline Technology 

Emissionsreduced, i is the Annual Emissions in year “i” for the Reduced Technology 

For example, for NOx emissions on the first year of the project: 

NOx Emissions baseline, 1 = 23.70 * 211,592 * 100% * (1 lb. / 453.6 grams) 

 = 10,945.21466 lbs 

NOx Emissionsreduced, 1 = 526.1196992 lbs 

NOx Emission Reductions (1) = 10,419.09496 lbs 

The following table contains EPA’s calculations of the annual emissions and emissions 

reductions for project G08GMCT1_03079. 

Project 

year 

Baseline Emissions (lbs) Reduced Emissions (lbs) Emission Reductions (lbs) 

NOx PM NOx PM NOx PM 

1 10,945.21 274.47 526.12 23.04 10,419.09 251.43 

2 11,037.10 281.97 643.71 27.63 10,393.39 254.34 

3 11,037.50 281.92 730.52 30.75 10,306.98 251.17 

4 11,039.55 282.26 840.99 34.94 10,198.56 247.33 

5 11,043.64 282.89 955.07 39.19 10,088.56 243.70 

Total 10,281.318 249.5935 

 

20 See Table “EMFAC'S FOR BASELINE EMISSION CALCULATION” in file “Prop 1B G08 2010 Guideline 

Year Emission Factors (Year 2 EFs).xlsx” included in email from Austin Hicks (ARB) to Idalia Perez (EPA R9), 

dated 4/21/2016. 

21 See Table “EMFAC'S FOR FUTURE EMISSION CALCULATIONS” in file “Prop 1B G08 2010 Guideline Year 

Emission Factors (Year 2 EFs).xlsx” included in email from Austin Hicks (ARB) to Idalia Perez (EPA R9), dated 

4/21/2016. 
U.S. EPA Region 9, Memorandum to File, April 26, 2016 

Sample emission reduction calculations for selected Carl Moyer and Prop 1B projects 

Docket No. EPA-R09-OAR-2015-0489 

8 

The total emission reductions during the 5-year project life are then averaged over five years to 

obtain annual emission reduction values. In addition, the average annual PM emission reductions 

are corrected to account for the percentage of total PM that is PM2.5 (92%), which equals 

229.626 lbs of PM2.5. The resulting numbers are consistent with the data in Appendix H.2 for 

project G08GMCT1_03079. 

The Table below shows the emission reduction values (in lbs/year) reported in Appendix H.2 of 

the Emission Reduction Report and the emission reductions calculated by EPA for the three 

randomly chosen projects subject to the 2010 Prop 1B guidelines. 

Equipment Project 

ID22

Reported 

NOx

Reported 

PM 

NOx calculated 

by EPA 

PM calculated 

by EPA 

G08GMCT1_03079 10281.32 229.63 10,281.32 299.63

G08GMCT1_00642 1725.00 164.04 1,725.00 165.82

G08GMCT1_02930 0.00 0.00 3374.45 1.47

As shown in the table, we have verified that the calculated emission reductions for all example 

projects were consistent to the second decimal. 

ARB’s calculated values for Project “G08GMCT1_02930” do not match EPA’s calculations, but 

ARB stated that “G08GMCT1_02930 was included in the submittal erroneously and should be 

removed from the submittal” and the report included zero NOx and PM emission reductions from 

this project. 23

 

22 Equipment Project IDs starting with “G08” are subject to the 2010 Prop 1B Guidelines. Equipment Project IDs 

starting with “G07” are subject to the 2008 Prop 1B Guidelines. 

23 See file “Attachement Prop 1B Input Data.xlsx” included in email from Sylvia Vanderspek (ARB) to Jeanhee 

Hong (EPA R9), dated 4/19/2016.